Turbo compressor and turbo refrigerator

ABSTRACT

A turbo compressor is provided including: a pump which sends lubricant stored in an oil tank having an open portion; and a control valve which adjusts the flow rate of the lubricant returning to the oil tank by dividing the stream of the lubricant sent from the pump; and an oil tank cover which blocks the open portion and is provided with an installation portion for the control valve, wherein the oil tank cover includes at least one of a first passage opened from the installation portion and allowing the stream of the lubricant sent from the pump to be divided and flow toward the control valve and a second passage opened from the installation portion and allowing the lubricant to flow from the control valve toward the oil tank.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a turbo compressor and a turbo refrigerator.

Priority is claimed on Japanese Patent Application No. 2010-081123, filed Mar. 31, 2010, the content of which is incorporated herein by reference.

2. Description of Related Art

Hitherto, as a refrigerator cooling or freezing a cooling object such as water, a turbo refrigerator has been known including a turbo compressor compressing a refrigerant through the rotation of an impeller and discharging the compressed refrigerant. The turbo compressor included in the turbo refrigerator includes sliding positions for bearings or gears sliding on the corresponding members with an operation of a drive unit such as a motor. Accordingly, for example, as disclosed in Patent Document 1 (Japanese Patent Application First Publication, No. 2009-257684), the turbo compressor includes a lubricant supply structure which supplies a lubricant for lubricating the sliding positions. The lubricant supply structure includes an oil tank which stores the lubricant and a pump sending the lubricant toward the sliding positions.

The lubricant supply structure may include a control valve that adjusts the flow rate of the lubricant supplied to the sliding positions. For example, the control valve is installed in a passage dividing the stream of the lubricant sent from the pump and returning to the oil tank.

However, since a plurality of pipes are provided between the pump and the control valve and between the control valve and the oil tank to connect them to each other, a problem arises in that the number of components, such as pipes, increases. Since the number of components increases, it becomes complicated to assemble the lubricant supply structure. Further, oil leaks are apt to occur at the connection positions of the pipes.

The present invention has been made in view of such circumstances, and an object thereof is to provide a turbo compressor capable of decreasing the number of components connected to a control valve, and a turbo refrigerator including the turbo compressor.

SUMMARY OF THE INVENTION

In order to solve the above-described problems, the present invention adopts the following configurations.

A turbo compressor according to the present invention is provided including: a pump which sends lubricant stored in an oil tank having an open portion; a control valve which adjusts the flow rate of the lubricant returning to the oil tank by dividing the stream of the lubricant sent from the pump; and an oil tank cover which blocks the open portion and is provided with an installation portion for the control valve, wherein the oil tank cover includes at least one of a first passage opened from the installation portion and allowing the stream of the lubricant sent from the pump to be divided and flow toward the control valve and a second passage opened from the installation portion and allowing the lubricant to flow from the control valve toward the oil tank.

According to the present invention, since at least one of the first passage and the second passage is opened from the installation portion, when the control valve is installed at the installation portion, at least one of the first passage and the second passage is directly connected to the control valve.

Further, the turbo compressor according to the present invention further includes an oil filter which is provided at the oil tank cover and filters the lubricant sent from the pump, wherein the first passage is provided to be divided from the passage between the pump and the oil filter.

According to the present invention, the lubricant flowing through the control valve returns to the oil tank without passing through the oil filter. For this reason, there are advantages in that the amount of lubricant filtered at the oil filter may be suppressed and the durability of the oil filter may be extended.

Further, in the turbo compressor according to the present invention, the installation portion is formed in a planar shape. According to the aspect of the present invention, there is an advantage in that the liquid tightness between the installation portion of the oil tank cover and the control valve may be easily ensured.

Further, a turbo refrigerator according to the present invention is provided including: a condenser which cools and liquefies a compressed refrigerant; an evaporator which evaporates the liquefied refrigerant and takes evaporation heat from a cooling object to cool the cooling object; and a compressor which compresses the refrigerant evaporated from the evaporator and supplies the compressed refrigerant to the condenser, wherein the turbo compressor according to the aspect may be used as the compressor.

According to the present invention, the following advantage may be obtained.

According to the present invention, since the control valve is installed at the installation portion, at least one of the first passage and the second passage is directly connected to the control valve. Accordingly, in the turbo compressor and the turbo refrigerator, there is an advantage in that the number of components, such as pipes, connected to the control valve may be decreased.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a schematic configuration of a turbo refrigerator of an embodiment of the present invention.

FIG. 2 is a horizontal cross-sectional view illustrating the turbo compressor of the embodiment of the present invention.

FIG. 3A is a schematic diagram illustrating a lubricant supply unit of the embodiment of the present invention.

FIG. 3B is a schematic diagram illustrating a lubricant supply unit of the embodiment of the present invention.

FIG. 3C is a schematic diagram illustrating a lubricant supply unit of the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an example embodiment of the present invention will be described by referring to FIGS. 1 to 3C. In the corresponding drawings used for the following description, the scales of the members are appropriately changed so that the members have recognizable sizes.

FIG. 1 is a block diagram illustrating a schematic configuration of a turbo refrigerator S1 of the embodiment. The turbo refrigerator S1 of the embodiment is installed at, for example, a building, a factory, or the like in order to generate air-conditioning cooling water, and includes a condenser 1, an economizer 2, an evaporator 3, and a turbo compressor 4.

A compressed refrigerant gas X1 as a compressed gas refrigerant is supplied to the condenser 1, and the compressed refrigerant gas X1 is cooled and liquefied therein so that it becomes a refrigerant liquid X2. Further, as shown in FIG. 1, the condenser 1 is connected to the turbo compressor 4 through a passage R1 where the compressed refrigerant gas X1 flows, and is connected to the economizer 2 through a passage R2 where the refrigerant liquid X2 flows. An expansion valve 5 is installed in the passage R2 so as to depressurize the refrigerant liquid X2.

The economizer 2 temporarily stores the refrigerant liquid X2 depressurized at the expansion valve 5. The economizer 2 is connected to the evaporator 3 through a passage R3 where the refrigerant liquid X2 flows, and is connected to the turbo compressor 4 through a passage R4 where a gas phase component X3 of the refrigerant generated at the economizer 2 flows. An expansion valve 6 is installed at the passage R3 so as to further depressurize the refrigerant liquid X2. Further, the passage R4 is connected to the turbo compressor 4 so as to supply the gas phase component X3 to a second compression stage 22 described later and provided in the turbo compressor 4.

The evaporator 3 cools a cooling object by taking evaporation heat from the cooling object such as water in a manner such that the refrigerant liquid X2 evaporates. The evaporator 3 is connected to the turbo compressor 4 through a passage R5 where a refrigerant gas X4 generated by the evaporation of the refrigerant liquid X2 flows. The passage R5 is connected to a first compression stage 21 described later and provided in the turbo compressor 4.

The turbo compressor 4 compresses the refrigerant gas X4 so that it becomes the compressed refrigerant gas X1. As described above, the turbo compressor 4 is connected to the condenser 1 through the passage R1 where the compressed refrigerant gas X1 flows, and is connected to the evaporator 3 through the passage R5 where the refrigerant gas X4 flows.

In the turbo refrigerator S1, the compressed refrigerant gas X1 supplied to the condenser 1 through the passage R1 is cooled and liquefied by the condenser 1 so that it becomes the refrigerant liquid X2. The refrigerant liquid X2 is depressurized by the expansion valve 5 when it is supplied to the economizer 2 through the passage R2, is temporarily stored in a depressurized state at the economizer 2. Then, the refrigerant liquid X2 is further depressurized by the expansion valve 6 when it is supplied to the evaporator 3 through the passage R3. Accordingly, the depressurized refrigerant liquid X2 is supplied to the evaporator 3. The refrigerant liquid X2 supplied to the evaporator 3 is evaporated by the evaporator 3 so that it becomes the refrigerant gas X4, and is supplied to the turbo compressor 4 through the passage R5. The refrigerant gas X4 supplied to the turbo compressor 4 is compressed by the turbo compressor 4 so that it becomes the compressed refrigerant gas X1, and is supplied again to the condenser 1 through the passage R1.

The gas phase component X3 of the refrigerant generated when the refrigerant liquid X2 is stored in the economizer 2 is supplied to the turbo compressor 4 through the passage R4, and is compressed together with the refrigerant gas X4 so that it is supplied as the compressed refrigerant gas X1 to the condenser 1 through the passage R1.

In the turbo refrigerator S1, the cooling object is cooled or frozen in a manner such that the refrigerant liquid X2 takes evaporation heat from the cooling object when evaporating from the evaporator 3.

Next, the turbo compressor 4 of the embodiment will be described in more detail. FIG. 2 is a horizontal cross-sectional view illustrating the turbo compressor 4 of the embodiment.

As shown in FIG. 2, the turbo compressor 4 of the embodiment includes a motor unit 10, a compressor unit 20, and a gear unit 30.

The motor unit 10 includes a motor 12 which includes an output shaft 11 and serves as a drive source which drives the compressor unit 20, and a motor casing 13 which surrounds the motor 12 and in which the motor 12 is installed. The drive source driving the compressor unit 20 is not limited to the motor 12. For example, an internal combustion engine may be used. The output shaft 11 of the motor 12 is rotatably supported by a first bearing 14 and a second bearing 15 fixed to the motor casing 13.

The compressor unit 20 includes the first compression stage 21 which suctions and compresses the refrigerant gas X4 (refer to FIG. 1), and the second compression stage 22 which further compresses the refrigerant gas X4 compressed at the first compression stage 21 and discharges it as the compressed refrigerant gas X1 (refer to FIG. 1).

The first compression stage 21 includes a first impeller 21 a which discharges the refrigerant gas X4 in the radial direction by applying kinetic energy to the refrigerant gas X4 supplied in the thrust direction, a first diffuser 21 b which compresses the refrigerant gas X4 by converting the kinetic energy applied to the refrigerant gas X4 into potential energy by the first impeller 21 a, a first scroll chamber 21 c (a scroll chamber) which guides the refrigerant gas X4 compressed by the first diffuser 21 b to the outside of the first compression stage 21, and a suction port 21 d which supplies the refrigerant gas X4 to the first impeller 21 a by suctioning the refrigerant gas X4. The first diffuser 21 b, the first scroll chamber 21 c, and the suction port 21 d are formed by a first impeller casing 21 e surrounding the first impeller 21 a.

The rotation shaft 23 is provided inside the compressor unit 20 so as to extend across the first compression stage 21 and the second compression stage 22. The first impeller 21 a is fixed to the rotation shaft 23, and the rotation shaft 23 rotates when rotation power is transmitted from the motor 12 thereto. Further, inlet guide vanes 21 f are provided in the suction port 21 d of the first compression stage 21 so as to adjust the suction amount of the first compression stage 21. Each inlet guide vane 21 f is rotatably supported by the drive mechanism 21 g fixed to the first impeller casing 21 e so that the apparent area in the stream direction of the refrigerant gas X4 is changeable. Further, a vane drive unit 24 is installed at the outside of the first impeller casing 21 e so that the vane drive unit is connected to the drive mechanism 21 g and rotationally drives each inlet guide vane 21 f.

The second compression stage 22 includes a second impeller 22 a which discharges the refrigerant gas X4 by applying kinetic energy to the refrigerant gas X4 compressed at the first compression stage 21 and supplied in the thrust direction, a second diffuser 22 b which compresses and discharges the compressed refrigerant gas X1 by converting the kinetic energy applied to the refrigerant gas X4 into potential energy using the second impeller 22 a, a second scroll chamber 22 c which guides the compressed refrigerant gas X1 discharged from the second diffuser 22 b to the outside of the second compression stage 22, and an introduction scroll chamber 22 d which guides the refrigerant gas X4 compressed by the first compression stage 21 to the second impeller 22 a. The second diffuser 22 b, the second scroll chamber 22 c, and the introduction scroll chamber 22 d are formed by a second impeller casing 22 e surrounding the second impeller 22 a.

The second impeller 22 a is fixed to the rotation shaft 23 so that the rear surface thereof is coupled to the rear surface of the first impeller 21 a, and rotates when rotation power is transmitted from the motor 12 to the rotation shaft 23. The second scroll chamber 22 c is connected to the passage R1 (refer to FIG. 1) supplying the compressed refrigerant gas X1 to the condenser 1 (refer to FIG. 1), and supplies the compressed refrigerant gas X1 guided out from the second compression stage 22 to the passage R1.

The first scroll chamber 21 c of the first compression stage 21 and the introduction scroll chamber 22 d of the second compression stage 22 are connected to each other through an external pipe (not shown) that is provided separately from the first compression stage 21 and the second compression stage 22. The refrigerant gas X4 compressed at the first compression stage 21 is supplied to the second compression stage 22 through the external pipe. The passage R4 (refer to FIG. 1) is connected to the external pipe, and the gas phase component X3 of the refrigerant generated at the economizer 2 is configured to be supplied to the second compression stage 22 through the external pipe.

The rotation shaft 23 is rotatably supported by a third bearing 26 fixed to the second impeller casing 22 e at a space 25 between the first compression stage 21 and the second compression stage 22 and a fourth bearing 27 fixed to the gear unit 30 of the second impeller casing 22 e.

The gear unit 30 is used to transmit rotation power of the motor 12 to the rotation shaft 23, and includes a spur gear 31 which is fixed to the output shaft 11, a pinion gear 32 which is fixed to the rotation shaft 23 and meshes with the spur gear 31, and a gear casing 33 which accommodates the spur gear 31 and the pinion gear 32. Furthermore, the gear unit 30 includes an oil tank 34 which is provided in the gear casing 33 and storing lubricant therein, a nozzle 35 which spraying and supplying lubricant to a sliding position sliding with the operation of the motor 12, a supply pipe 36 which is connected to the nozzle 35, and a lubricant supply unit 40 (hereinafter, simply referred to as a “supply unit 40”) which sends lubricant stored in the oil tank 34 toward the supply pipe 36 and the nozzle 35. As the above-described sliding positions, a bearing such as a fourth bearing 27 or a meshing portion between the spur gear 31 and the pinion gear 32 may be mentioned.

The spur gear 31 has an outer diameter larger than that of the pinion gear 32, and transmits the rotation power of the motor 12 to the rotation shaft 23 so that the rpm of the rotation shaft 23 increases with respect to the rpm of the output shaft 11 by the corporation between the spur gear 31 and the pinion gear 32. The transmission method is not limited thereto, and the diameters of the plurality of gears may be set so that the rpm (number of rotations) of the rotation shaft 23 is equal to or lower than the rpm of the output shaft 11.

The gear casing 33 is molded separately from the motor casing 13 and the second impeller casing 22 e, and connects them each other. The interior of the gear casing 33 is provided with an accommodation space 33 a that accommodates the spur gear 31, the pinion gear 32, the nozzle 35, and the supply pipe 36.

The oil tank 34 is a tank that is used to collect and store lubricant supplied to the sliding position with the operation of the motor 12 and lubricating the sliding position. The lubricant stored in the oil tank 34 may contain minute metal powder or sludge formed at the sliding position.

The nozzle 35 sprays and supplies lubricant to the sliding position of the fourth bearing 27 or the meshing portion between the spur gear 31 and the pinion gear 32 to lubricate the sliding position. The supply pipe 36 is a pipe member that is provided between the nozzle 35 and the supply unit 40 and supplying lubricant to the nozzle 35. Another nozzle may be provided to supply lubricant to the sliding position of the first bearing 14 or the third bearing 26.

Next, the supply unit 40 which is the characteristic point of the embodiment will be described in more detail. FIGS. 3A to 3C are schematic diagrams the supply unit 40 of the embodiment, where FIG. 3A is a front view, FIG. 3B is a plan view, and FIG. 3C is a side view. The supply unit 40 includes a pump 41, an oil filter 42, a first blocking valve 43, a second blocking valve 44, and a control valve 45. The pump 41, the oil filter 42, the first blocking valve 43, the second blocking valve 44, and the control valve 45 are all installed at an oil tank cover 46. The oil tank cover 46 is provided to seal an open portion 34 a formed in the oil tank 34. The oil tank cover 46 is molded by, for example, casting, and is fixed to the oil tank 34 through fastening bolts 46 a. The second supply pipe 47 is connected to the supply unit 40. The second supply pipe 47 is a pipe member that is connected to the supply pipe 36 (refer to FIG. 2).

The pump 41 is installed at the rear surface of the oil tank cover 46, and is provided inside the oil tank 34. The pump 41 sends lubricant stored in the oil tank 34 toward the first pre-filtering passage 46 b formed in the oil tank cover 46. The discharge amount from the pump 41 is set to be constant. The oil filter 42 is installed in a filter installation space 46 c formed at the front surface of the oil tank cover 46 so as to be replaceable when necessary. The oil filter 42 filters the lubricant sent from the pump 41 and removes minute metal powder or sludge contained in the lubricant.

The first blocking valve 43 is provided at the front surface of the oil tank cover 46. The first blocking valve 43 is connected to the pump 41 through the first pre-filtering passage 46 b. Further, the first blocking valve 43 is connected to the filter installation space 46 c through the second pre-filtering passage 46 d formed in the oil tank cover 46. Further, the first blocking valve 43 is a valve that blocks the stream of the lubricant flowing toward the oil filter 42 by interrupting the connection between the first pre-filtering passage 46 b and the second pre-filtering passage 46 d. The first blocking valve 43 is opened or closed by an operation of a first handle 43 a.

The second blocking valve 44 is provided between the filter installation space 46 c and the second supply pipe 47 at the front surface side of the oil tank cover 46. The second blocking valve 44 is a valve that blocks the stream of the lubricant flowing toward the supply pipe 36 by interrupting the connection between the filter installation space 46 c and the second supply pipe 47. The second blocking valve 44 is opened or closed by an operation of a second handle 44 a.

The control valve 45 is a valve that adjusts the flow rate of the lubricant returning to the oil tank 34 by dividing the stream of the lubricant sent from the pump 41. The control valve 45 is installed at an installation portion 46 e formed in the oil tank cover 46. The surface of the control valve 45 facing the installation portion 46 e is formed in a planar shape. This surface is provided with an inflow hole and an outflow hole (not shown). The flow rate of the lubricant flowing from the inflow hole into the control valve 45 and flowing out from the outflow hole is adjustable. The flow rate of the lubricant is adjusted by an operation of a third handle 45 a.

The installation portion 46 e is formed in a planar shape. A gasket (a seal member, not shown in figure) is interposed between the control valve 45 and the installation portion 46 e so as to liquid-tightly seal therebetween. The gasket is provided with penetration holes which correspond to the inflow hole and the outflow hole of the control valve 45. The surface of the control valve 45 facing the installation portion 46 e and the installation portion 46 e are both formed in a planar shape. Accordingly, the liquid-tightness therebetween may be ensured.

The oil tank cover 46 is provided with a dividing passage 46 f (a first passage) and a returning passage 46 g (a second passage). The dividing passage 46 f is divided from the filter installation space 46 c and is opened from the installation portion 46 e. That is, the dividing passage 46 f is provided to be divided from the passage between the pump 41 and the oil filter 42. The open position of the dividing passage 46 f in the installation portion 46 e is set to a position facing the inflow hole of the control valve 45. As described above, since the gasket is interposed between the control valve 45 and the installation portion 46 e, the dividing passage 46 f is liquid-tightly connected to the inflow hole of the control valve 45. That is, the dividing passage 46 f is directly connected to the filter installation space 46 c and the control valve 45. The dividing passage 46 f is formed by extension hole portions which extend in a predetermined direction, and the predetermined end portion of the extension hole is sealed by a set screw 46 h (a slotted set screw) threaded thereinto.

The returning passage 46 g is provided between the installation portion 46 e and the rear surface of the oil tank cover 46. One end of the returning passage 46 g is opened from the installation portion 46 e, and the other end thereof is opened from the rear surface of the oil tank cover 46 (that is, the interior of the oil tank 34). The open position of the returning passage 46 g in the installation portion 46 e is set to a position facing the outflow hole of the control valve 45. As described above, since the gasket is interposed between the control valve 45 and the installation portion 46 e, the returning passage 46 g is liquid-tightly connected to the outflow hole of the control valve 45. That is, the returning passage 46 g is directly connected to the interior of the oil tank 34 by the control valve 45.

A lubricant supply operation of the supply unit 40 will be described.

First, the first blocking valve 43 and the second blocking valve 44 are opened by the operation of the first handle 43 a and the second handle 44 a. By the operation of the pump 41, the lubricant stored in the oil tank 34 is sent toward the first pre-filtering passage 46 b. The lubricant sent to the first pre-filtering passage 46 b flows into the filter installation space 46 c through the first blocking valve 43 and the second pre-filtering passage 46 d. The lubricant is filtered while flowing into the oil filter 42 provided in the filter installation space 46 c. By this filtering, minute metal powder or sludge contained in the lubricant is removed. The lubricant filtered by the oil filter 42 is sent to the second supply pipe 47 through the second blocking valve 44. The lubricant sent to the second supply pipe 47 is supplied to the nozzle 35 through the supply pipe 36, and is sprayed from the nozzle 35 to the sliding position.

Part of the lubricant flowing into the filter installation space 46 c flows through the dividing passage 46 f and flows into the control valve 45. The lubricant passing through the control valve 45 and flowing out from the control valve 45 flows through the returning passage 46 g and returns into the oil tank 34 again. By the operation of the third handle 45 a, it is possible to adjust of the flow rate of the lubricant divided from the filter installation space 46 c, flowing through the dividing passage 46 f, the control valve 45, and the returning passage 46 g, and returning into the oil tank 34. When the flow rate of the lubricant passing through the control valve 45 and returning to the oil tank 34 increases, the flow rate of the lubricant passing through the second supply pipe 47 and flowing toward the nozzle 35 decreases. For this reason, it is possible to adjust the flow rate of the lubricant supplied to the sliding position of the turbo compressor 4 by operating the third handle 45 a. As described above, the lubricant supply operation in the supply unit 40 is completed.

Since the dividing passage 46 f and the returning passage 46 g are opened from the installation portion 46 e, when the control valve 45 is provided in the installation portion 46 e, the dividing passage 46 f and the returning passage 46 g are both directly connected to the control valve 45. Accordingly, it is possible to decrease the number of components such as pipes connecting the control valve 45 to the pump 41 and the oil tank 34. When the number of components is decreased, it is possible to simplify the assembly of the supply unit 40 and to suppress oil leakage.

Further, the lubricant returning into the oil tank 34 through the control valve 45 is the lubricant divided before passing through the oil filter 42. For this reason, it is possible to suppress the amount of the lubricant filtered at the oil filter 42 and to extend the durability of the oil filter 42.

Next, an operation of the turbo compressor 4 of the embodiment will be described.

First, rotation power of the motor 12 is transmitted to the rotation shaft 23 through the spur gear 31 and the pinion gear 32. Accordingly, the first impeller 21 a and the second impeller 22 a of the compressor unit 20 are rotationally driven.

When the first impeller 21 a is rotationally driven, the suction port 21 d of the first compression stage 21 becomes a negative pressure state, and the refrigerant gas X4 flows from the passage R5 into the first compression stage 21 through the suction port 21 d. The refrigerant gas X4 flowing into the first compression stage 21 flows into the first impeller 21 a in the thrust direction, and is discharged in the radial direction while kinetic energy is applied thereto by the first impeller 21 a. The refrigerant gas X4 discharged from the first impeller 21 a is compressed by the first diffuser 21 b by converting kinetic energy into potential energy. The refrigerant gas X4 discharged from the first diffuser 21 b is guided to the outside of the first compression stage 21 through the first scroll chamber 21 c. The refrigerant gas X4 guided to the outside of the first compression stage 21 is supplied to the second compression stage 22 through an external pipe (not shown).

The refrigerant gas X4 supplied to the second compression stage 22 flows into the second impeller 22 a in the thrust direction through the introduction scroll chamber 22 d, and is discharged in the radial direction while kinetic energy is applied thereto by the second impeller 22 a. The refrigerant gas X4 discharged from the second impeller 22 a is further compressed by converting kinetic energy into potential energy by the second diffuser 22 b, so that it becomes the compressed refrigerant gas X1. The compressed refrigerant gas X1 discharged from the second diffuser 22 b is guided the outside of the second compression stage 22 through the second scroll chamber 22 c. The compressed refrigerant gas X1 guided to the outside of the second compression stage 22 is supplied to the condenser 1 through the passage R1.

As described above, the operation of the turbo compressor 4 is completed.

According to the embodiment, the following advantages may be obtained.

According to the embodiment, there is an advantage in that the number of supply pipes or nozzles supplying the lubricant to the fourth bearing 27 and the meshing portion 38 may be decreased. Further, in the turbo compressor 4 and the turbo refrigerator S1 including the turbo compressor, there is an advantage in that manufacturing effort and cost may be reduced.

While preferred embodiments of the present invention have been described and illustrated above, it should be understood that these are examples of the present invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the present invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.

For example, in the above-described embodiment, the dividing passage 46 f and the returning passage 46 g are both opened from the installation portion 46 e, but the present invention is not limited thereto. For example, any one of them may be opened from the installation portion 46 e. Only by a configuration in which one passage is opened from the installation portion 46 e, the number of components such as pipes may be decreased.

Further, in the above-described embodiment, the dividing passage 46 f is divided from the filter installation space 46 c, but the present invention is not limited thereto. For example, the dividing passage may be divided from the passage through which the lubricant filtered at the oil filter 42 flows.

Further, in the above-described embodiment, the installation portion 46 e is formed in a planar shape, but only the gap between the installation portion 46 e and the control valve 45 may be liquid-tightly sealed. For example, a step portion may be provided between the dividing passage 46 f and the returning passage 46 g in the installation portion 46 e. 

1. A turbo compressor comprising: a pump which sends lubricant stored in an oil tank having an open portion; a control valve which adjusts the flow rate of the lubricant returning to the oil tank by dividing the stream of the lubricant sent from the pump; and an oil tank cover which blocks the open portion and is provided with an installation portion for the control valve, wherein the oil tank cover includes at least one of a first passage opened from the installation portion and allowing the stream of the lubricant sent from the pump to be divided and flow toward the control valve and a second passage opened from the installation portion and allowing the lubricant to flow from the control valve toward the oil tank.
 2. The turbo compressor according to claim 1, further comprising: an oil filter which is provided at the oil tank cover and filters the lubricant sent from the pump, wherein the first passage is provided to be divided from the passage between the pump and the oil filter.
 3. The turbo compressor according to claim 1, wherein the installation portion is formed in a planar shape.
 4. The turbo compressor according to claim 2, wherein the installation portion is formed in a planar shape.
 5. A turbo refrigerator comprising: a condenser which cools and liquefies a compressed refrigerant; an evaporator which evaporates the liquefied refrigerant and takes evaporation heat from a cooling object to cool the cooling object; and a compressor which compresses the refrigerant evaporated from the evaporator and supplies the compressed refrigerant to the condenser, wherein the turbo compressor according to claim 1 is used as the compressor.
 6. A turbo refrigerator comprising: a condenser which cools and liquefies a compressed refrigerant; an evaporator which evaporates the liquefied refrigerant and takes evaporation heat from a cooling object to cool the cooling object; and a compressor which compresses the refrigerant evaporated from the evaporator and supplies the compressed refrigerant to the condenser, wherein the turbo compressor according to claim 2 is used as the compressor.
 7. A turbo refrigerator comprising: a condenser which cools and liquefies a compressed refrigerant; an evaporator which evaporates the liquefied refrigerant and takes evaporation heat from a cooling object to cool the cooling object; and a compressor which compresses the refrigerant evaporated from the evaporator and supplies the compressed refrigerant to the condenser, wherein the turbo compressor according to any one of claim 3 is used as the compressor.
 8. A turbo refrigerator comprising: a condenser which cools and liquefies a compressed refrigerant; an evaporator which evaporates the liquefied refrigerant and takes evaporation heat from a cooling object to cool the cooling object; and a compressor which compresses the refrigerant evaporated from the evaporator and supplies the compressed refrigerant to the condenser, wherein the turbo compressor according to claim 4 is used as the compressor. 